Method for dishing reduction and feature passivation in polishing processes

ABSTRACT

Methods and apparatus for planarizing a substrate surface are provided. In one aspect, a method is provided for planarizing a substrate surface including polishing a first conductive material to a barrier layer material, depositing a second conductive material on the first conductive material by an electrochemical deposition technique, and polishing the second conductive material and the barrier layer material to a dielectric layer. In another aspect, a processing system is provided for forming a planarized layer on a substrate, the processing system including a computer based controller configured to cause the system to polish a first conductive material to a barrier layer material, deposit a second conductive material on the first conductive material by an electrochemical deposition technique, and polish the second conductive material and the barrier layer material to a dielectric layer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of co-pending U.S. patent applicationSer. No. 09/939,323, filed Aug. 24, 2001, which is incorporated hereinby reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to the fabrication ofsemiconductor devices and to chemical mechanical polishing, deposition,and planarization of semiconductor devices.

2. Background of the Related Art

Reliably producing sub-half micron and smaller features is one of thekey technologies for the next generation of very large scale integration(VLSI) and ultra large-scale integration (ULSI) of semiconductordevices. However, as the fringes of circuit technology are pressed, theshrinking dimensions of interconnects in VLSI and ULSI technology hasplaced additional demands on the processing capabilities. The multilevelinterconnects that lie at the heart of this technology require preciseprocessing of high aspect ratio features, such as vias, contacts, lines,and other interconnects. Reliable formation of these interconnects isimportant to VLSI and ULSI success and to the continued effort toincrease circuit density and quality of individual substrates and die.

To further improve the current density of semiconductor devices onintegrated circuits, it has become necessary to use conductive materialshaving low resistivity for conductors. One conductive material gainingacceptance is copper and its alloys, which have become the materials ofchoice for sub-quarter-micron interconnect technology because copper hasa lower resistivity than aluminum, (1.7 μΩ-cm compared to 3.1 μΩ-cm foraluminum), and a higher current carrying capacity. These characteristicsare important for supporting the higher current densities experienced athigh levels of integration and increased device speed. Further, copperhas a good thermal conductivity and is available in a highly pure state.

One difficulty in using copper in semiconductor devices is that copperis difficult to etch and achieve a precise pattern. Etching with copperusing traditional deposition/etch processes for forming interconnectshas been less than satisfactory. Therefore, new methods of manufacturinginterconnects having copper containing materials are being developed.

One method for forming vertical and horizontal interconnects is by adamascene or dual damascene method. In the damascene method, one or moredielectric materials, such as the low k dielectric materials, aredeposited and pattern etched to form the vertical interconnects, i.e.vias, and horizontal interconnects, i.e., lines. Conductive materials,such as copper, and other materials, such as barrier layer materialsused to prevent diffusion of conductive material into the surroundinglow k dielectric, are then inlaid into the etched pattern. Any excessconductive material and excess barrier layer material external to theetched pattern, such as on the field of the substrate, is then removed.Barrier layer materials include, for example, tantalum (Ta), tantalumnitride (TaN), titanium (Ti), and titanium nitride.

As layers of materials are sequentially deposited and removed, theuppermost surface of the substrate may become non-planar across itssurface and require planarization. Planarizing a surface, or “polishing”a surface, is a process where material is removed from the surface ofthe substrate to form a generally even, planar surface. Planarization isuseful in damascene processes to remove excess deposited material and toprovide an even surface for subsequent levels of metallization andprocessing. Planarization may also be used in removing undesired surfacetopography and surface defects, such as rough surfaces, agglomeratedmaterials, crystal lattice damage, scratches, and contaminated layers ormaterials.

Chemical mechanical planarization, or chemical mechanical polishing(CMP), is a common technique used to planarize substrates. Inconventional CMP techniques, a substrate carrier or polishing head ismounted on a carrier assembly and positioned in contact with a polishingpad in a CMP apparatus. The carrier assembly provides a controllablepressure to the substrate urging the substrate against the polishingpad. The pad is moved relative to the substrate by an external drivingforce. Thus, the CMP apparatus effects polishing or rubbing movementbetween the surface of the substrate and the polishing pad whiledispersing a polishing composition to effect both chemical activity andmechanical activity.

Conventionally, in polishing copper features, such as dual damascenefeatures, the copper material is polished to the barrier layer, and thenthe barrier layer is polished to the underlying dielectric layer.However, the interface between copper and the barrier layer is generallynon-planar and copper materials and the barrier materials are oftenremoved from the substrate surface at different rates, which can resultin the retention of copper material, or residue, on the surface of thesubstrate. To ensure removal of all the copper material and residuebefore removing the barrier material, it is necessary to overpolish thecopper at the interface. Overpolishing of copper at the interface canresult in forming topographical defects, such as concavities, recesses,or depressions, referred to as dishing, in copper features.

FIG. 1 is a schematic view of a substrate illustrating the phenomenon ofdishing. Conductive lines 12 and 14 are formed by depositing conductivematerials, such as copper or copper alloy, in a feature definitionformed in the dielectric layer 10, typically comprised of silicon oxidesor other dielectric materials. After planarization, a portion of theconductive material is depressed by an amount D, referred to as theamount of dishing, forming a recess 16 in the copper surface. Dishingresults in a non-planar surface that impairs the ability to printhigh-resolution lines during subsequent photolithographic steps anddetrimentally affects subsequent surface topography of the substrate anddevice formation. Dishing also detrimentally affects the performance ofdevices by lowering the conductance and increasing the resistance of thedevices, contrary to the benefit of using higher conductive materials,such as copper.

Therefore, there exists a need for a method and apparatus thatplanarizes a substrate surface with minimal or reduced dishing of thesubstrate surface.

SUMMARY OF THE INVENTION

The invention generally provides a method and apparatus for planarizinga substrate surface to minimize dishing of substrate features. In oneaspect, a method is provided for processing a substrate includingproviding a substrate with feature definitions formed in a dielectricmaterial, depositing a barrier layer material on a substrate surface andin the feature definitions, depositing a first conductive material onthe barrier layer material to fill the feature definitions, polishingthe first conductive material to at least a top surface of the barrierlayer material, depositing a second conductive material by anelectrochemical deposition technique on at least the first conductivematerial to fill recesses formed in the first conductive material, andpolishing the second conductive material and the barrier layer materialto at least a top surface of the dielectric layer to form a planarsurface.

In another aspect, a method is provided for planarizing a substratesurface including providing a substrate to a polishing station disposedon a processing system, wherein the substrate comprises a dielectricmaterial with substrate feature definitions formed therein, a barrierlayer material disposed thereon and within the feature definitions, anda copper material disposed on the barrier layer material, polishing thecopper material from the substrate surface to at least a top surface ofthe barrier layer material, transferring the substrate to anelectrochemical deposition and polishing station disposed on thepolishing system, depositing a conductive material selectively on thecopper containing material by an electroless deposition technique whileremoving the conductive material and the barrier layer material to atleast a top surface of the dielectric layer by a polishing technique.

In another aspect, a processing system is provided for forming aplanarized layer on a substrate surface including a processing platformhaving two or more processing stations, a loading station, and asubstrate transfer device disposed above the processing stations and theloading station, wherein at least one of the processing stations isadapted to polish a substrate surface, wherein at least one of theprocessing stations is adapted to deposit a material by anelectrochemical process, and a computer based controller configured tocause the system to polish a first conductive material from thesubstrate surface to a barrier layer material, deposit a secondconductive material on the first conductive material by anelectrochemical deposition technique, and polish the second conductivematerial and the barrier layer material to at least the top surface of adielectric layer.

Another aspect of the invention provides a substrate processing chamberadapted for processing a substrate including a substrate support,comprising a substrate receiving surface, a vacuum port, vacuum groovesin communication with the vacuum port, and a fluid source, a fluid inputcoupled to the fluid source and adapted to deliver a processing fluid toa substrate disposed on the substrate receiving surface, and a fluidoutput adapted to drain the processing fluid from the processingchamber. The substrate processing chamber may further include apolishing head assembly including polishing media and a polishing mediasupport.

The substrate processing chamber may be disposed in an electrochemicaldeposition system including a mainframe having a mainframe wafertransfer robot, a loading station disposed in connection with themainframe, one or more polishing platens disposed in connection with themainframe, an electrolyte supply fluidly connected to the substrateprocessing chamber, and one or more polishing fluid supplies connectedto the one or more polishing platens

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited aspects of the inventionare attained and can be understood in detail, a more particulardescription of the invention, briefly summarized above, may be had byreference to the embodiments thereof which are illustrated in theappended drawings.

It is to be noted, however, that the appended drawings illustrate onlytypical embodiments of this invention, and the drawings are thereforenot to be considered limiting of the scope of the invention because theinvention may admit to other equally effective embodiments.

FIG. 1 is a schematic view of a substrate illustrating the phenomenon ofdishing;

FIG. 2 is a plan view of one embodiment of a processing platformincorporating embodiments of the processing apparatus of the invention;

FIG. 3 is a plan view of another embodiment of a processing platformincorporating embodiments of the processing apparatus of the invention;

FIG. 4 is a schematic view of one embodiment of a polishing station thatmay conduct polishing with a conventional or abrasive sheet polishingpad;

FIG. 5 is a cross sectional view of one embodiment of an apparatus thatmay deposit and polish a material by an electrochemical process;

FIGS. 6A-6C are cross sectional views of further embodiments of anapparatus that may deposit and polish a material by an electrochemicalprocess;

FIG. 7 is a flow chart illustrating the processing steps according toone aspect of the invention; and

FIGS. 8A-8D are schematic diagrams illustrating one embodiment of aprocess for forming a feature on a substrate.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

In general, aspects of the invention provide a method and apparatus forreducing or minimizing dishing and recess formation from polishing ofconductive materials, such as copper. The invention will be describedbelow in reference to treating a substrate surface between chemicalmechanical polishing (CMP) techniques and electrochemical depositiontechniques. CMP is broadly defined herein as polishing a substrate bychemical activity, mechanical activity, or a combination of bothchemical and mechanical activity. Electrochemical deposition processesare broadly described herein by the deposition of material by anelectron exchange mechanism, such as by a chemical reduction method.

FIG. 2 depicts one embodiment of a processing system 100 having at leastone electrochemical processing station 102 and at least one conventionalpolishing or buffing station 106 for performing the processes describedherein. One polishing tool that may be adapted to benefit from theinvention is a MIRRA MESA® chemical mechanical polisher available fromApplied Materials, Inc. located in Santa Clara, Calif. The exemplarysystem 100 generally comprises a factory interface 108, a loading robot110, and a depositing and planarizing module 112. Generally, the loadingrobot 110 is disposed proximate the factory interface 108 and thedepositing and planarizing module 112 to facilitate the transfer ofsubstrates 122 therebetween.

The factory interface 108 generally includes a cleaning module 114 andone or more substrate cassettes 116. An interface robot 118 is employedto transfer substrates 123 between the substrate cassettes 116, thecleaning module 114 and an input module 120. The input module 120 ispositioned to facilitate transfer of substrates 123 between thedepositing and planarizing module 112 and the factory interface 108 bythe loading robot 110.

Processed substrates 123 are typically passed from the input module 120through the cleaning module 114 before the factory interface robot 118returns the cleaned substrates 123 to the cassettes 116. An example ofsuch a factory interface 108 that may be used to advantage is disclosedin U.S. patent application Ser. No. 09/547,189, filed Apr. 11, 2000,assigned to common assignee Applied Materials, Inc., and which is herebyincorporated by reference.

The loading robot 110 is generally positioned proximate the factoryinterface 108 and the depositing and planarizing module 112 such thatthe range of motion provided by the robot 110 facilitates transfer ofthe substrates 123 therebetween. An example of a loading robot 110 is a4-Link robot, manufactured by Kensington Laboratories, Inc., located inRichmond, Calif. The exemplary loading robot 110 has a gripper 111 thatmay orientate the substrate 123 in either a vertical or a horizontalorientation.

The exemplary depositing and planarizing module 112 has a transferstation 122 and a carousel 134 in addition to the electrochemicalprocessing station 102 and the polishing station 106, all of which aredisposed on a machine base 126. The depositing and planarizing module112 may comprise one or more processing stations, such as one or morepolishing stations and one or more electrochemical processing stations.In a further alternative, a polishing module 112 may be provided forpolishing a substrate following processing by the methods describedherein or in the apparatus described herein.

In one embodiment, the transfer station 122 comprises at least an inputbuffer station 128, an output buffer station 130, a transfer robot 132,and a load cup assembly 124. The transfer robot 132 has two gripperassemblies, each having pneumatic gripper fingers that grab thesubstrate 123 by the substrate's edge. The transfer robot 132 lifts thesubstrate 123 from the input buffer station 128 and rotates the gripperand substrate 123 to position the substrate 123 over the load cupassembly 134, then places the substrate 123 down onto the load cupassembly 124. An example of a transfer station that may be used toadvantage is described by Tobin in U.S. patent application Ser. No.09/314,771, filed Oct. 10, 1999, assigned to common assignee AppliedMaterials, Inc., and which is hereby incorporated by reference.

The carousel 134 is generally described in U.S. Pat. No. 5,804,507,issued Sep. 8, 1998 to Tolles et al. and is hereby incorporated hereinby reference in its entirety. Generally, the carousel 134 is centrallydisposed on the base 126. The carousel 134 typically includes aplurality of arms 136. The arms 136 generally each supporting apolishing head 138 while one arm supports a carrier head assembly 104.One of the arms 136 depicted in FIG. 2 is shown in phantom such that thetransfer station 122 may be seen. The carousel 134 is indexable suchthat the polishing head 138 and carrier head assembly 104 may be movedbetween the modules 102, 106 and the transfer station 122.

Generally the polishing head 138 retains the substrate 123 whilepressing the substrate against a polishing material (not shown) disposedon the polishing stations 106. One polishing head that may be utilizedis a TITAN HEAD™ substrate carrier manufactured by Applied Materials,Inc., Santa Clara, Calif.

The arrangement of the electrochemical processing stations 102 andpolishing stations 106 on the depositing and planarizing module 112allow for the substrate 123 to be sequentially plated or polishing bymoving the substrate between processing stations. The substrate 123 maybe processed in each station 102, 106 while remaining in it respectivehead or carrier assembly 104, 138, or the substrate may be switchedbetween heads by offloading the substrate from one head into the loadcup and loading into the substrate into the other polishing head.Optionally, the depositing and planarizing module 112 may comprise onlyone type of head may be utilized (i.e., all polishing heads 138 or allcarrier heads 104).

Further, while not shown, a computer system or computer based controlleror a computer program-product may be connected to the system 100 forinstructing the system to perform one or more processing steps on thesystem, such as polishing a substrate, electrochemical depositingmaterial on a substrate, or transferring a substrate in the system 100.

Programs defining functions of aspects of the invention can be providedto a computer via a variety of signal-bearing media and/or computerreadable media, which include but are not limited to, (i) informationpermanently stored on non-writable storage media (e.g. read-only memorydevices within a computer such as read only CD-ROM disks readable by aCD-ROM or DVD drive; (ii) alterable information stored on a writablestorage media (e.g. floppy disks within diskette drive or hard-diskdrive); or (iii) information conveyed to a computer by communicationsmedium, such as through a computer or telephone network, includingwireless communication.

Such signal-bearing media, when carrying computer-readable instructionsthat direct the functions of the invention, represent alternativeaspects of the invention. It may also be noted that portions of theproduct program may be developed and implemented independently, but whencombined together are aspects of the invention.

To facilitate control of the system 100 as described above, computerbased controller 140 may be a CPU 144 or one of any form of computerprocessor that can be used in an industrial setting for controllingvarious chambers and subprocessors. Memory 142 is coupled to the CPU 144and the memory, or computer-readable medium, may be one or more ofreadily available memory such as random access memory (RAM), read onlymemory (ROM), floppy disk, hard disk, or any other form of digitalstorage, local or remote. Support circuits 146 are coupled to the CPU144 for supporting the processor in a conventional manner. Thesecircuits include cache, power supplies, clock circuits, input/outputcircuitry and subsystems, and the like. Process sequences, such as byaspects of the processes described herein, is generally stored in thememory, typically as a software routine. The software routine may alsobe stored and/or executed by a second CPU (not shown) that is remotelylocated from the hardware being controlled by the CPU 144.

Another system useful for performing the processes described herein isshown in FIG. 3. FIG. 3 depicts a schematic top view of anotherembodiment of a processing system 200 having at least oneelectrochemical processing station 218 and at least one conventionalpolishing station 215 for performing the processes described herein. Onetool that may be adapted to benefit from the invention is an ELECTRA®processing system available from Applied Materials, Inc. located inSanta Clara, Calif. An example of a suitable electroplating tool isdescribed in co-pending U.S. patent application Ser. No. 09/289,074,filed on Apr. 8, 2000, assigned to common assignee Applied Materials,Inc., and which is incorporated by reference herein to the extent notinconsistent with the invention.

The system 200, an electroplating system platform, generally comprises aloading station 210, a mainframe 214, one or more electrochemicalprocessing stations 218, one or more polishing stations 215. The systemmay also contain a thermal anneal chamber 211, an electrolytereplenishing system 220, and one or more substrate pass-throughcassettes 238.

The mainframe 214 generally comprises a mainframe transfer station 216,a spin-rinse dry (SRD) station 212, a plurality of electrochemicalprocessing stations 218, and one or more polishing stations 215. Thesystem 200, particularly the mainframe 214, is enclosed in a cleanenvironment using panels such as Plexiglas panels. The mainframe 214includes a base having cutouts to support various stations needed tocomplete the electrochemical deposition process.

Each processing station 218 includes one or more electrochemicalprocessing cells 240. An electrolyte replenishing system 220 ispositioned adjacent the mainframe 214 and connected to the process cells240 individually to circulate electrolyte used for the electroplatingprocess.

Each polishing station 215 comprises one or more polishing platens 217.The polishing platens 217 may comprise a stationary polishing platen, arotatable polishing platen, a linear polishing platen, a rotatablelinear polishing platen, a roller polishing platen, or combinationsthereof. Polishing media disposed on the polishing platens 217 may beconductive and/or contain abrasive elements or particles.

The system 200 also includes a power supply station 221 for providingelectrical power to the system and a control system 222, typicallycomprising a programmable microprocessor. The power supply includes oneor more power sources that may be connected to individualelectrochemical cells 240 and polishing platens 217. The control system222 is mounted above the mainframe 214 and comprises a programmablemicroprocessor. The programmable microprocessor is typically programmedusing software designed specifically for controlling all components ofthe system 200. The control system 222 also provides electrical power tothe components of the system and includes a control panel that allows anoperator to monitor and operate the system 200. The control panel is astand-alone module that is connected to the control system 222 through acable and provides easy access to an operator. Generally, the controlsystem 222 coordinates the operations of the various components of thesystem 200, such as the loading station 210, the RTA chamber 211, theSRD station 212, the mainframe 214, the processing stations 218 and 215,and the electrolyte replenishing system 220 to provide the electrolytefor the electroplating process.

The loading station 210 preferably includes one or more substratecassette receiving areas 224, one or more loading station transferrobots 228 and at least one substrate orientor 230. A number ofsubstrate cassette receiving areas, loading station transfer robots 228and substrate orientor included in the loading station 210 can beconfigured according to the desired throughput of the system.

The system 200 has a modular design that allows for the replacement ofcomponents for a desired configuration for performing a process orsequence of processes. For example, the electrochemical processingstations 218 may be replaced with a polishing station 215, and viceversa.

Additionally, individual components of the stations, such as the one ormore polishing platens 217 of the polishing stations 215, may bedisposed at the locations of other processing components, such as thethermal anneal chamber 211 and one or more substrate pass-throughcassettes 238. Alternative embodiment may have electroless depositionstations at the location of the one or more polishing stations 215 ifthe one or more polishing platens 217 are disposed at the locations ofthe thermal anneal chamber 211 and the one or more substratepass-through cassettes 238.

As shown for one embodiment in FIG. 3, the loading station 210 includestwo substrate cassette receiving areas 224, two loading station transferrobots 228 and one substrate orientor 230. A substrate cassette 232containing substrates 234 is loaded onto the substrate cassettereceiving area 224 to introduce substrates 234 into the system 200. Theloading station transfer robot 228 transfers substrates 234 between thesubstrate cassette 232 and the substrate orientor 230. The loadingstation transfer robot 228 comprises a typical transfer robot commonlyknown in the art.

The substrate orientor 230 positions each substrate 234 in a desiredorientation to ensure that the substrate is properly processed. Theloading station transfer robot 228 also transfers substrates 234 betweenthe loading station 210 and the SRD station 212 and between the loadingstation 210 and the thermal anneal chamber 211. The loading station 210preferably also includes a substrate cassette 231 for temporary storageof substrates as needed to facilitate efficient transfer of substratesthrough the system.

FIG. 3 also shows a mainframe transfer robot 242 having a flipper robot244 incorporated therein. The mainframe transfer robot 242 serves totransfer substrates between different stations attached to the mainframestation, including the electrochemical processing stations 218 and thepolishing stations 215. The mainframe transfer robot 242 includes aplurality of robot arms 242 (two shown), and a flipper robot 244 isattached as an end effector for each of the robot arms 246. Flipperrobots are generally known in the art and can be attached as endeffectors for substrate handling robots, such as model RR701, availablefrom Rorze Automation, Inc., located in Milpitas, Calif.

The main transfer robot 242 having a flipper robot 244 as the endeffector is capable of transferring substrates between differentstations attached to the mainframe as well as flipping the substratebeing transferred to the desired surface orientation. For example, theflipper robot 244 flips the substrate processing surface face-down forthe electroplating process in the processing cell 240 or polishingprocess in the polishing platens of the polishing station 215, and flipsthe substrate processing surface face-up for other processes, such asthe spin-rinse-dry process or substrate transfer. The mainframe transferrobot 242 provides independent robot motion along the X-Y-Z axes by therobot arm 246 and independent substrate flipping rotation by the flipperrobot end effector 244. The flipper robot 244 are used withelectrochemical processing cells 240 adapted to electroplate a substratedisposed on a flipper or adapted to receive a substrate from a flipperrobot prior to performing an electrochemical process.

Alternatively, a substrate carrier (as shown in FIG. 1) may be disposedin place of the mainframe transfer robot 242 to transfer between and/orprocess substrates in the one or more electrochemical processingstations 218 and the one or more polishing stations 215.

The rapid thermal anneal (RTA) chamber 211 is preferably connected tothe loading station 210, and substrates are transferred into and out ofthe RTA chamber 211 by the loading station transfer robot 228. Theelectroplating system may comprises two RTA chambers 211 disposed onopposing sides of the loading station 210, corresponding to thesymmetric design of the loading station 210, in one embodiment. Anexample of a suitable anneal chamber is a rapid thermal anneal chamber,such as the RTP XEplus Centura® thermal processor available from AppliedMaterials, Inc., Santa Clara, Calif.

The electrolyte replenishing system 220 provides the electrolyte to theelectroplating process cells 240 for the electroplating and/or anodicdissolution process. The electrolyte replenishing system 220 generallycomprises a main electrolyte tank 260, a plurality of source tanks 262,and a plurality of filter tanks 264. One or more controllers control thecomposition of the electrolyte in the main tank 260 and the operation ofthe electrolyte replenishing system 220. Preferably, the controllers areindependently operable but integrated with the control system 222 of thesystem 200.

The main electrolyte tank 260 provides a reservoir for electrolyte andincludes an electrolyte supply line that is connected to each of theelectroplating process cells. The source tanks 262 contain the chemicalsneeded for composing the electrolyte and typically include a deionizedwater source tank and copper sulfate (CuSO₄) source tank for composingthe electrolyte. Other source tanks 262 may contain hydrogen sulfate(H₂SO₄), hydrogen chloride (HCl), hydrogen phosphate (H₂PO₄), and/orvarious additives including corrosion inhibitors and leveling agents,such as polyglycols.

Additionally, while not shown, one or more supply tanks are connected tosystem 200 to provide one or more polishing fluids, conditioning fluids,and/or cleaning fluids, to the one or more polishing stations 215disposed thereon.

FIG. 4 is a schematic view of one embodiment of a polishing station 106and polishing head 138 as shown in FIG. 2 that may conduct polishingwith a conventional or abrasive sheet polishing pad. The polishingstation 106 comprises a polishing pad assembly 345 secured to an uppersurface of a rotatable platen 341. The platen 341 is coupled to a motor346 or other suitable drive mechanism to impart rotational movement tothe platen 341. During operation, the platen 341 is rotated at avelocity V_(p) about a center axis X. The platen 341 can be rotated ineither a clockwise or counterclockwise direction.

FIG. 4 also shows the polishing head 138 mounted above the polishingstation 106. The polishing head 138 supports a substrate 123 forpolishing. The polishing head 138 may comprise a vacuum-type mechanismto chuck the substrate 123 against the polishing head 138. Duringoperation, the vacuum chuck generates a negative vacuum force behind thesurface of the substrate 123 to attract and hold the substrate 123. Thepolishing head 138 typically includes a pocket (not shown) in which thesubstrate 123 is supported, at least initially, under vacuum. Once thesubstrate 123 is secured in the pocket and positioned on the padassembly 345, the vacuum can be removed. The polishing head 138 thenapplies a controlled pressure behind the substrate, indicated by thearrow 348, to the backside of the substrate 123 urging the substrate 123against the pad assembly 345 to facilitate polishing of the substratesurface. The polishing head displacement mechanism 337 rotates thepolishing head 138 and the substrate 123 at a velocity V_(s) in aclockwise or counterclockwise direction, preferably the same directionas the platen 341. The polishing head displacement mechanism 337 alsopreferably moves the polishing head 138 radially or orbitally across theplaten 341 in a direction indicated by arrows 350 and 352.

The CMP system also includes a chemical supply system 354 forintroducing chemical slurry of a desired composition to the polishingpad. In some applications, the slurry provides an abrasive material thatfacilitates the polishing of the substrate surface, and may be achemical mechanical polishing composition that may optionally includeabrasive materials, such as solid alumina or silica. During operation,the chemical supply system 354 introduces the slurry, as indicated byarrow 356, on the pad assembly 345 at a selected rate. In otherapplications the pad assembly 345 may have abrasive particles disposedthereon and require only that a liquid, such as deionized water, bedelivered to the polishing surface of the pad assembly 345.

The pad assembly 345 may comprise a conventional polishing pad or anabrasive sheet polishing pad. The abrasive sheet polishing pad includesa 5-200 mil thick abrasive composite layer, composed of abrasive grainsheld or embedded in a binder material. The abrasive grains may have aparticle size between about 0.1 and 1500 microns, and have a Mohs'hardness of at least 8, such as silica, ceria, or alumina. The bindermaterial may be derived from a precursor that includes an organicpolymerizable resin, which is cured from the binder material, such aspolyurethane. Abrasive sheet pads are available from 3M Corporation ofMinneapolis, Minn. and Rodel Inc., of Phoenix Ariz.

The pad assembly 345 may include a conventional polishing pad or“abrasive-free” polishing pad, i.e., a polishing pad that does not haveembedded abrasive particles, having a smooth polishing surface or aroughened polishing surface. A suitable soft polishing pad is availablefrom Rodel, Inc., of Phoenix, Ariz., under the trade name Politex andIC-1000. The polishing pad may be embossed or stamped with a pattern toimprove distribution of slurry across the face of the substrate.

FIG. 5 is a cross sectional view of one embodiment of a processingstation 102 for performing an electrochemical deposition process. Oneexample of an apparatus that may be adapted to benefit from theinvention is the processing system described in FIGS. 2 and 3.

The processing station 102 generally includes a carrier head assembly104 movably supported by a stanchion 480 over a partial enclosure 434.The stanchion 480 and enclosure 434 are generally disposed on a commonbase 482. The stanchion 480 generally includes a base support 484 and alift mechanism 486. The base support 484 extends perpendicularly fromthe base 482 and may be rotatable on its axis so that the carrierassembly 104 may be moved over the partial enclosure 434 or to otherpositions, for example, to other enclosures or to interface with otherprocessing systems not shown.

The lift mechanism 486 is coupled to the carrier assembly 104. The liftmechanism 486 generally controls the elevation of the carrier assembly104 in relation to the partial enclosure 434. The lift mechanism 486includes be a linear actuator 88, such as a ball screw, lead screw,pneumatic cylinder and the like, and a guide 490 that slides along arail 492. The rail 492 is coupled to the base support 484 by a hinge 494so that the rail 492 of the lift mechanism 486 (i.e., direction ofmotion) may be controllably orientated through a range of angles betweenabout 90 to about 60 degrees relative to horizontal. The lift mechanism486 and hinge 494 allows the carrier assembly 104 holding a substrate123 to be lowered into the partial enclosure 434 in variousorientations. For example, to minimize the formation of bubbles upon thesubstrate 123 when interfacing with fluids disposed within the enclosure434, the substrate 123 may be orientated at an angle during entry intothe partial enclosure 434 and then rotated to a horizontal orientationonce therein.

The partial enclosure 434 generally defines a container or electrolytecell in which an electrolyte or polishing/deposition fluid can beconfined. The electrolyte used in processing the substrate 123 caninclude metals such as copper, aluminum, tungsten, gold, silver,platinum, nickel, tin, cobalt, doped versions thereof, and alloysthereof, or other materials which can be electrochemically deposited,such as by an electroplating deposition process, an electrolessdeposition process, or an electrochemical mechanical plating processtechnique (ECMPP), onto a substrate. An ECMPP process is broadlydescribed herein as an electrochemical deposition technique thatenhances planarization of materials during deposition using polishingtechniques.

As one example, copper sulfate (CuSO₄) can be used as the electrolyte.Copper containing solutions used for plating are available from ShipleyRodel, a division of Rohm and Haas, headquartered in Philadelphia, Pa.,under the tradename Ultrafill 2000. The invention also contemplates theuse of any known or commercially available electroless andelectroplating chemistries.

The enclosure 434 may includes an anode/cathode 426 for electroplatingdeposition processes, a diffuser plate 444, and a permeable disk 428,which may be used in a deposition and polishing technique, disposedtherein.

The partial enclosure 434 can be a bowl shaped member made of a plasticsuch as fluoropolymers, TEFLON®, PFA, PE, PES, or other materials thatare compatible with plating chemistries. The partial enclosure 434 isconnected to a shaft 432 on its lower surface that extends below thebase 482. Alternatively, the partial enclosure 434 can be connected to amounting platform that is connected to the shaft 432. The shaft 432 isconnected to an actuator (not shown), such as a motor, e.g., a steppermotor, disposed in the base 482. The actuator is adapted to rotate thepartial enclosure 434 about vertical axis x. In one embodiment, theshaft 432 defines a central passage through which fluid is deliveredinto the partial enclosure 434 through a plurality of ports 36 formed inthe shaft 432.

The anode/cathode 426 is positioned at the lower portion of theenclosure 434 where it may be immersed in the electrolyte solution. Theanode/cathode may perform as either an anode or a cathode depending uponthe positive bias (anode) or negative bias (cathode) applied to it. Forexample, depositing material from an electrolyte on the substratesurface, the anode/cathode 426 acts as an anode and the substratesurface acts as a cathode. When removing material from a substratesurface, such as by dissolution from an applied bias, the anode/cathode426 functions as a cathode and the wafer surface or permeable disk 428may act as an anode for the dissolution process.

The anode/cathode 426 can be a plate-like member, a plate havingmultiple holes formed therethrough or a plurality of pieces disposed ina permeable membrane or container. The anode/cathode 426 may becomprised of the material to be deposited. In at least one embodiment,the anode/cathode 426 comprises a consumable anode/cathode that mayrequire periodic replacement. Alternatively, the anode/cathode maycomprise non-consumable anode/cathode of a material other than thedeposited material, such as platinum for a copper deposition or removal.

In at least one embodiment, the anode/cathode 426 is ring-shapeddefining a central opening through which the fluid inlet of the shaft432 is disposed. In embodiments where the anode/cathode 426 isplate-like, a plurality of holes may be formed through the anode/cathodeto allow passage of electrolyte fluid therethrough. The anode/cathode426 can alternatively be a ring anode/cathode, a plate anode/cathode, ora chamber confining plating material, including a permeable chamber orother enclosure.

The permeable disk 428 can be a polishing pad or other type of volumespacer that is compatible with the fluid environment and the processingspecifications. When incorporated with the station 104, the permeabledisk 428 is positioned at an upper end of the partial enclosure 434 andsupported on its lower surface by the diffuser plate 444. The permeabledisk 428 is preferably conductive to ions in the electrolyte, and assuch does not have to be permeable to metal ions, such as copper ions,for example, in copper applications. The metal ions can be supplied froma fluid delivery line 440 having an outlet 442 positioned above thepermeable disk 428. The permeable disk 428 may disposed adjacent to orin contact with the anode/cathode 426.

The permeable disk 428 may comprise a plurality of pores of a sufficientsize and organization to allow the flow of electrolyte to the substratesurface while preventing the flow of deposition by-products, such asaccelerator and suppressor degradation by-products. The permeable disk428 may also comprise grooves formed therein to assist transport offresh electrolyte from the solution into enclosure 434 to the gapbetween the substrate 422 and the permeable disk 428. However, thepermeable disk 428 can be permeable to metal ions in some applications.

The permeable disk 428 includes polishing media, such as a polishing padcomprised of polymeric materials, such as polyurethane, for performingelectrochemical mechanical polishing processes during or subsequent todeposition processes. Examples of polishing pads that can be usedinclude, but are not limited to, an IC 1000, an IC 1010, a Suba seriespad, a Politex series pad, a MHS series pad from Rodel, Inc., ofPhoenix, Ariz., or a PVDF pad from Asahi of Japan, or a abrasive sheetpad from 3M, of Minneapolis, Minn.

The permeable disk may be polishing media including conductive materialfor electroplating deposition process. For an electroplating deposition,the conductive polishing media may comprise a conductive polymer, or apolymer, such as polyurethane, with conductive elements or materials(not shown) embedded or formed therein, to provide a conductive pathover the polishing media. The conductive elements are electricallyconnected to one another in the polishing media and may contact thesubstrate surface when the substrate is in contact with the polishingmedia. Alternatively the polishing media may form an insulator material,or a material of low conductance, such as polyurethane for a depositionprocess.

The diffuser plate 444 provides support for the permeable disk 428 inthe partial enclosure 434. The diffuser plate 444 can be secured in thepartial enclosure 434 using fasteners such as screws 438 or other meanssuch as snap or interference fit with the enclosure, being suspendedtherein and the like. The diffuser plate 444 can be made of a materialsuch as a plastic, e.g., fluoropolymer, PE, TEFLON®, PFA, PES, HDPE,UHMW or the like. The diffuser plate 444, in at least one embodiment,includes a plurality of holes or channels 446 formed therein. The holes446 are sized to enable fluid flow therethrough and to provide uniformdistribution of electrolyte through the permeable disk 428 to thesubstrate 123.

The permeable disk 428 can be fastened to the diffuser plate 444 usingadhesives that are compatible with the fluid environment and theprocessing requirements. The diffuser plate 444 is preferably spacedfrom the anode/cathode 426 to provide a wider process window, thusreducing the sensitivity of plating film thickness to the anode/cathodedimensions, and to separate the accelerator and suppressor decompositionby-products, for example, a mono-sulfide compound degraded from anaccelerator, such as bis(3-sulfopropyl) disulfide, C₆H₁₂Na₂O₆S₄,commercially available from the Raschig Corp. of Germany, from a mainplating volume 438 defined between the permeable disk 428 and thesubstrate 123.

While not shown, a membrane may be disposed between the anode/cathode426 and the permeable disk 428 to contain particles produced from theanode/cathode film from entering the enclosure 434 and depositing asparticles on the substrate surface. For example, the membrane ispermeable to electrolyte flow, but is not typically permeable toaccelerator and suppressor degradation by-products on the anode/cathodesurface.

The substrate carrier or head assembly 104 is movably positioned abovethe permeable disk 428. The substrate carrier assembly 104 is verticallymovable above the permeable disk 428 and is laterally movable thereto,for example, the carrier assembly 104 may be rotatable about a verticalaxis y. The x and y axis of the partial enclosure and the head assembly,respectively, are offset to provide orbital motion between the permeabledisk 428 and the substrate carrier assembly 104. Orbital motion isbroadly described herein as an elliptical relative motion between thepermeable disk 428 and the substrate carrier assembly 104. The substratecarrier assembly 104 holds a substrate 123 with the deposition surfacefacing down towards the permeable disk 428. Alternatively, the permeabledisk 428 may comprise a surface which may move in a translational orlinear relative motion as well as rotatable, or circular rotational,relative motion to the substrate carrier assembly 104.

The substrate carrier assembly 104 generally includes a drive system468, a head assembly 478 and a seat assembly 476. The drive system 468is generally coupled to the guide 490 of the stanchion 480. The drivesystem 468 comprises a column 470 that extends from a power head 456 tosupport the seat assembly 476. The power head 456, which may be anelectric or pneumatic motor, generally provides rotation to the column470 along a central axis. The drive system 486 additionally includes anactuator 454 that is disposed within the column 470 and is coupled tothe head assembly 478. The actuator 454, which may be a lead screw,pneumatic cylinder or other linear actuator, allows the head assembly478 to move in relation to the seat assembly 476.

The seat assembly 476 generally includes a plurality of gripper fingers474 disposed in a polar array about a gripper plate 472. The gripperplate 472 is coupled to the column 70 so that the gripper plate 472moves with the drive system 468. In one embodiment, three gripperfingers 474 are provided. The gripper fingers 474 generally include abase member 466, an extension 464 and a contact finger 462. The contactfingers 462 are disposed at an angle to the extension 464. The extension464 is coupled to the base member 466. The base member 466 is rotatablycoupled to the gripper plate 472. The base member 466 generally includesan aperture that aligns with a hole in the gripper plate 472. A clevispin or other shaft member is disposed through the hole and aperture toallow rotation of the gripper finger 474 in relation to the gripperplate 472. An actuator 460 is coupled between the extension 464 and thegripper plate 472. The actuator 460 moves the gripper finger 474 betweenan open and closed position. A spring 458 may be optionally disposed onthe clevis pin to bias the gripper finger 474 towards one position. Whenthe contact fingers 462 are moved inward, a notch 452 disposed at theends of each contact finger 462 defines a seat 450 that is adapted toreceive the substrate 123 from a transfer robot (not shown). In theinward position, the extensions 464 are disposed at a distance from eachother that allows the substrate 422 and robot to pass therebetween (notshown).

FIGS. 6A-6C show schematic cross-sectional views of other embodiments ofa processing station 602 useful for the deposition and removal of aconductive material layer as described herein. For example, theprocessing station 602 may be disposed at station 102 as shown in FIG. 2or at stations 215 or 218 in FIG. 3. The processing station on FIG. 6Amay be used for electroless deposition of a conductive material on asubstrate surface. The station 602 includes a processing compartment 602comprising a top 604, sidewalls 606, and a bottom 607. A substratesupport 612 is disposed in a generally central location in the station602.

The substrate support 612 includes a substrate receiving surface 614 toreceive the substrate 610 in a “face-up” position. In one aspect, havingthe substrate 610 disposed on the substrate support 612 in a “face-up”position reduces the possibility of bubbles in a fluid when applied tothe substrate 610 from affecting the processing of the substrate 610.For example, bubbles may be created in the fluid in-situ or may becreated by transferring of a wet substrate. If the substrate weredisposed in a “face-down position” during processing, bubbles in thefluid would be trapped against the surface of the substrate as a resultof the buoyancy of the bubbles. Having the substrate in a “face-up”position reduces bubbles in the fluid from being situated against thesurface of the substrate since buoyant forces pressure the bubbles torise up in the fluid. Having the substrate in a face-up position alsolessens the complexity of the substrate transfer mechanisms, improvesthe ability to clean the substrate during processing, and allows thesubstrate to be transferred in a wet state to minimize contaminationand/or oxidation of the substrate.

The station 602 further includes a slot 608 or opening formed through awall thereof to provide access for a robot (not shown) to deliver andretrieve the substrate 610 to and from the station 602. A lift assembly616 may be disposed below the substrate support 612 to raise and lowerthe substrate support 612 or raise and lower the substrate 610 to andfrom the substrate receiving surface 614 of the substrate support 612. Amotor 624 may be coupled to the substrate support 612 to rotate thesubstrate support 612 to spin the substrate 610. The substrate supportmay be adapted to rotate the substrate in a clockwise direction orcounter-clockwise direction.

The substrate support 612 may be heated to heat the substrate 610 to adesired temperature. The substrate receiving surface 614 of thesubstrate support 612 may be sized to substantially receive the backsideof the substrate 610 to provide uniform heating of the substrate 610.Uniform heating of a substrate is an important factor in order toproduce consistent processing of substrates, especially for depositionprocesses having deposition rates that are a function of temperature.The substrate support 612 may further be coupled to a power source (notshown) typically a DC power source to bias the substrate support 612.

A nozzle 623 may be disposed in the station 602 to deliver a fluid, suchas a chemical processing solution, deionized water, and/or an acidsolution, to the surface of the substrate 610. The nozzle 623 may bedisposed over the center of the substrate 610 to deliver a fluid to thecenter of the substrate 610 or may be disposed in any position. Thenozzle 623 may be disposed on a dispense arm 622 positioned over the top604 or through the sidewall 616 of the processing compartment 602. Thedispense arm 622 may be moved about a rotatable support member 621 whichis adapted to pivot and swivel the dispense arm 622 and the nozzle 623to and from the center of the substrate 610. Additionally oralternatively, a nozzle (not shown) may be disposed on the top 604 orsidewalls 606 of the station 602 and adapted to spray a fluid in anydesired pattern to the substrate 610. A single or a plurality of fluidsources (not shown) may be coupled to the nozzle 623 to provide aplurality of different types of fluids. Alternatively, the components ofthe processing compartment 602 may be hermetically sealed to provide forfiling the processing compartment with an electrolyte prior to substratetransfer and processing.

In one embodiment, the substrate support 612 may be adapted to rotate atrelatively slow speeds, such as between about 10 RPMs and about 500RPMs, depending on the viscosity of the fluid, to spread the fluidacross the surface of the substrate 610 by centrifugal force. Thesubstrate support 612 may be adapted to spin in alternating directionsin a back-and-forth motion to assist in spreading the fluid evenlyacross the surface of the substrate 610. In one embodiment, the dispensearm 622 is adapted to move during dispense of the fluid to improve fluidcoverage of the substrate 610.

The substrate support 612 may rotate during dispensing of a fluid fromthe nozzle 623 in order to increase throughput of the system. In someinstances, the substrate support 612 may be adapted to spin atrelatively medium speeds, such as between about 100 RPMs and about 500RPMs, to rinse the substrate 610 with a fluid. In other instances, thesubstrate support may be adapted to spin at relatively fast speeds, suchas between about 500 RPMS and about 2000 RPMs to spin dry the substrate610.

The station 602 further includes a drain 627 in order to collect andexpel fluids used in the station 602. The bottom 607 of the processingcompartment 602 may comprise a sloped surface to aid the flow of fluidsused in the chamber 610 towards the drain 627 and to protect thesubstrate support assembly 613 from contact with fluids.

The substrate support 612 may include a vacuum port (not shown) coupledto a vacuum source (not shown) to supply a vacuum to the backside of thesubstrate to vacuum chuck the substrate 610 to the substrate support612. Vacuum Grooves may be formed on the substrate support 612 incommunication with the vacuum port to provide a more uniform vacuumpressure across the backside of the substrate 610. In one aspect, thevacuum chuck improves heat transfer between the substrate 610 and thesubstrate support 612. In addition, the vacuum chuck holds the substrate610 during rotation of the substrate support 612. While not shown, aheater may be disposed in the substrate support 612 for heating thesubstrate suring processing.

FIGS. 6B and 6C show a processing station 602 that may be used forelectroless deposition and polishing of a conductive material and/orbarrier layer materials on a substrate surface. A polishing headassembly 630 is used to contact a substrate surface and remove materialstherefrom. The polishing head assembly includes polishing media 632,polishing media support 634, optionally, a spacer 636, and, furtheroptionally, an electrode 638.

The polishing media 632 may be a conventional polishing media, such aspolyurethane or polyurethane composites, including the IC-1000 polishingpad, from Rodel Inc., of Phoenix, Ariz. The polishing media 632 may alsoinclude a conductive polishing material or a composite of a conductivepolishing material disposed in a conventional polishing material. Theconductive polishing material may include conductive polymers, polymercomposites with conductive materials, conductive metals, conductivefillers or conductive doping materials, or combinations thereof.

Generally, the conductive polishing material or the composite of theconductive polishing material and conventional polishing material areprovided to produce a conductive polishing media having a bulkresistivity or a bulk surface resistivity of about 10 Ω-cm or less. Anexample of a composite of the conductive polishing material andconventional polishing material includes carbon fibers or carbonnanotubes, both of which exhibit resistivities of 1 Ω-cm or less,disposed in a conventional polishing material of polycarbonate orpolyurethane in sufficient amounts to provide a polishing media having abulk resistivity of about 10 Ω-cm or less. The conductive polishingmedia 632 is generally perforated to allow for electrolyte flowtherethrough.

Alternatively, the polishing media 632 may comprise a metal meshdisposed in the conventional polishing material. The metal mesh maycomprise a chemically inert conductive material, such as platinum, whichhas a resistivity 9.81 μΩ-cm at 0° C. The metal mesh may also includematerials that have been observed to react with the surroundingelectrolyte, such as copper which has a resistivity of 1.6 μΩ-cm at 0°C., if the metal mesh is chemically insulated from the electrolyte suchas by a conformal layer of conventional material.

The polishing media support 634 can be made of materials which includeconductive noble metals, such as platinum, or a conductive polymer toprovide electrical conduction across the polishing media. The polishingmedia support 634 is used to provide for uniform bias or current tominimize conductive resistance along the surface of the media, forexample, the radius of the media, during polishing for uniform anodicdissolution across the substrate surface. The polishing media support634 is generally connected to a power source (not shown) and providesthe current carrying capability, i.e., the anodic bias for anodicdissolution, of the conductive polishing media 632. The polishing mediasupport may also be perforated for flow of electrolyte therethrough. Thepolishing media 632 and polishing media support 634 generally form afirst electrode for performing either a plating process or anelectropolish process to deposit or remove material, respectively, fromthe substrate surface.

The spacer 636 generally comprises a rigid support material used to holdthe polishing media 632 and the polishing media support 634. The spacer636 may include a conductive material or an insulative material. Thespacer 636 may include polymeric material, for example fluoropolymers,PE, TEFLON®, PFA, PES, HDPE, UHMW or the like, and may include aconventional hard polishing material, for example, materials found inthe IC series of polishing media, such as polyurethane or polyurethanecomposites, including the IC-1000 polishing pad, from Rodel Inc., ofPhoenix, Ariz.

The electrode 638 may be an anode or cathode depending upon the positivebias (anode) or negative bias (cathode) applied between the electrode204 and polishing media 632. For example, depositing material from anelectrolyte on the substrate surface, the electrode 638 acts as an anodeand the substrate surface and/or polishing media 632 acts as a cathode.When removing material from a substrate surface, such as by dissolutionfrom an applied bias, the electrode 638 functions as a cathode and thesubstrate surface and/or polishing media 632 may act as an anode for thedissolution process.

The electrode 638 can be a plate-like member, a plate having multipleholes formed therethrough or a plurality of electrode pieces disposed ina permeable membrane or container, and is generally contacting orimmersed in the electrolyte. The electrode 638 may be comprised of thematerial to be deposited or removed, such as copper, aluminum, gold,silver, tungsten and other materials which can be electrochemicallydeposited on the substrate. However, for electrochemical removalprocesses, such as anodic dissolution, the electrode 638 may include anon-consumable electrode of a material other than the depositedmaterial, such as platinum for copper dissolution. The non-consumableelectrode is used in planarization processes combining bothelectrochemical deposition and removal.

The polishing head assembly may be rotated at a rate between about 10rpms and about 200 rpms during polishing. The polishing head may berotated in a clockwise direction or a counter-clockwise direction. Thepolishing head may be adapted to rotate in the same or oppositedirection as the substrate support 612.

The polishing head assembly may have a smaller diameter than thesubstrate. The polishing head assembly may be moved over the substratesurface during the polishing process to polish selected portions of thesubstrate surface at selected intervals to provide for effectiveplanarization of the substrate surface. The polishing head assembly maybe controlled to polish the substrate surface in a predetermined orrandom pattern. The polishing head assembly may be further controlled topolish selected portions of the substrate surface for selective periodsof time. For example, the substrate may be polished in an ellipticalpattern, or the edges of the substrate may be polished more than thecenter of the substrate, or only a selected portion, i.e., the center ofthe substrate, is polished. The above polishing examples are provided toillustrate aspects described herein, and are not to be construed orinterpreted as limiting the scope of the invention.

Chemical Mechanical Polishing Process and Composition.

The words and phrases used herein should be given their ordinary andcustomary meaning in the art by one skilled in the art unless otherwisefurther defined. Chemical-mechanical polishing should be broadlyconstrued and includes, but is not limited to, abrading a substratesurface by chemical activity, mechanical activity, or a combination ofboth chemical and mechanical activity. Electropolishing should bebroadly construed and includes, but is not limited to, planarizing asubstrate by the application of electrochemical activity.

Electrochemical mechanical polishing (ECMP) should be broadly construedand includes, but is not limited to, planarizing a substrate by theapplication of electrochemical activity, mechanical activity, or acombination of both electrochemical and mechanical activity to removematerial from a substrate surface. Electrochemical mechanical platingprocess (ECMPP) should be broadly construed and includes, but is notlimited to, electrochemically depositing material on a substrate andconcurrently planarizing the deposited material by the application ofelectrochemical activity and mechanical activity.

Electrochemical deposition processes are broadly described herein by thedeposition of material by an electron exchange mechanism, such as by achemical reduction method. Electroplating is broadly defined herein asthe deposition of a conductive material generally provided as chargedions in a bath by the application of an external electrical current toreduce the ions and deposit material. Electroless deposition is broadlydefined herein as deposition of a conductive material generally providedas charged ions in a bath over a catalytically active surface to depositthe conductive material by chemical reduction in the absence of anexternal electric current.

A substrate surface processed by the methods and compositions describedherein generally comprises a dielectric layer with feature definitionsformed therein, a barrier layer deposited on the dielectric layer, and aconductive material, for example, copper containing material, depositedon the barrier layer. Other conductive materials for filling featuredefinitions formed in the dielectric layer include aluminum, tungsten,and combinations thereof. The conductive material may be deposited bychemical vapor deposition, physical vapor deposition, electrolessdeposition, electroplating, or combinations thereof.

As used throughout this disclosure, material designations, such as thephrase “copper containing material”, “copper”, and the symbol Cu, areintended to encompass elemental materials, such as elemental copper,doped elemental materials, such as doped copper, e.g., phosphorous dopedcopper, and element based alloys, such as copper-based alloys, e.g.,copper-based alloys containing at least about 80 wt. % copper. Forexample, the material designation of “cobalt” is intended to encompasselemental cobalt, cobalt alloys, and doped cobalt, such as cobaltphosphate.

The barrier layer material includes tantalum-containing materials, suchas tantalum, tantalum nitride, or tantalum silicon nitride. Otherbarrier materials for conductive materials used in aluminum, copper, andtungsten metallization processes include titanium, titanium nitride,tungsten, tungsten nitride, PVD titanium stuffed with nitrogen, dopedsilicon, aluminum, aluminum oxides, titanium silicon nitride, tantalumsilicon nitride, tungsten silicon nitride, and combinations thereof. Thebarrier layer materials may be deposited by chemical vapor deposition,physical vapor deposition, electroless deposition, electroplating, orcombinations thereof.

The dielectric layer can comprise any of various dielectric materialsconventionally employed in the manufacture of semiconductor devices. Forexample, dielectric materials, such as silicon dioxide, phosphorus-dopedsilicon glass (PSG), boron-phosphorus-doped silicon glass (BPSG), andsilicon dioxide derived from tetraethyl orthosilicate (TEOS) or silaneby plasma enhanced chemical vapor deposition (PECVD) can be employed.The dielectric layer can also comprise low dielectric constantmaterials, including fluoro-silicon glass (FSG), polymers, such aspolyamides, and carbon-containing silicon dioxide, such as BlackDiamond™, commercially available from Applied Materials, Inc., of SantaClara, Calif. Generally, the dielectric layer is formed by a chemicalvapor deposition technique or a spin-on glass techniques. The openingsare formed in interlayer dielectrics by conventional photolithographicand etching techniques.

One planarizing process for reducing or minimizing dishing or recessesformed in a substrate surface generally includes polishing a firstconductive material from the substrate surface to a barrier layer,depositing a second conductive material on the first conductive materialby an electrochemical deposition technique, and polishing the substrateto the dielectric layer.

FIG. 7 is a flow chart illustrating the processing steps for planarizinga substrate surface according to one embodiment of the invention. Theprocess generally includes positioning a substrate in a first polishingstation at step 700, polishing the substrate at the polishing stationuntil a first conductive material is removed to the barrier layer atstep 710, transferring the substrate to an electrochemical depositionstation at a second processing station at step 720, depositing a secondconductive material on the first conductive material by anelectrochemical deposition process at step 730, transferring thesubstrate to a second polishing station at step 740, and polishing thesubstrate at the second polishing station until the second conductivematerial and the barrier layer material is removed to a dielectric layerat step 750.

In one aspect, the planarizing process begins by providing a substrateto a processing system, for example, positioning a substrate in asubstrate carrier assembly 138, and then positioning the substrate inthe polishing station 106 at step 700. The substrate typically includesa dielectric layer with feature definitions formed therein, a barrierlayer conformally deposited on the dielectric layer and in the featuredefinitions formed therein, and a first conductive material deposited onthe barrier layer and filling the feature definitions formed therein asdescribed above.

Polishing the substrate at the polishing station to remove at least aportion of the conductive material is performed in step 710. In oneaspect of this polishing step, the conductive material is removed to thelevel of the barrier layer. The level of the barrier layer includes thetop surface of the barrier layer or may include some intermediate levelbetween the top surface of the barrier layer and the bottom surface ofthe barrier layer.

The conductive material may be removed by a polishing composition on aconventional or abrasive sheet polishing pad. The polishing compositionused with the conventional polishing pad may be an abrasive-containingpolishing composition or an abrasive-free polishing composition.Abrasive-containing compositions generally include abrasive particles,such as silica, alumina, or ceria disposed in the solution whileabrasive-free composition polish the substrate in the absence ofabrasive particles in the solution. Abrasive-free solutions aretypically used with an abrasive sheet polishing pad having a pluralityof elements comprising abrasive particles in a resin binder disposed ona flexible backing. For example, copper containing material can beremoved using an abrasive-free polishing composition capable of removingcopper containing material with minimal removal of a tantalum barriermaterial on a abrasive sheet pad.

Suitable polishing compositions for removing the conductive material,such as copper containing material, in the first polishing step includeHC 430-A1-3, HS-C430-A3, HS-C435, HS-A2, commercially available fromHitachi Chemical Co. Ltd., of Japan. Examples of other suitablepolishing compositions, including abrasive-containing polishingcompositions and abrasive-free polishing compositions, commerciallyavailable for removing copper containing material in the first polishingstep on a hard pad include EPC-5003, EPC-5001, and EPC-5306, availablefrom Cabot Corp. of Aurora, Ill., Copper S1 3116, Copper S1 3280, andCopper S1 3125, available from Rodel Inc., of Newark, Del., MicroplanarCMP9000, CMP9003, and CMP9011, available from EKC Technology Inc., ofHayward Calif., Eterpol EPL 2352, EPL 2311, EPL 1405, EPL 1453, EPL2315, EPL 2313, and Eterpol 765057, available from Eternal ChemicalCompany Ltd. Of Taiwan, DP-191 and DP-200, available from DupontChemical of Wilmington, Del.

Following the first polishing step 710, the substrate is transferred toa substrate carrier assembly 104, and positioned in the electrochemicaldeposition station 102 at a second processing station at Step 720 asshown in FIG. 7. The substrate is positioned in the partial enclosure 34containing an electrolyte, and optionally, an anode. The substrate maybe electrically connected to a power source (not shown) and function asa cathode during the electrochemical deposition process. At least thesurface of the substrate is in contact with an electrolyte solution, andthe entire substrate may be submerged in the electrolyte solution. Theelectrolyte solution is provided to the partial enclosure 34 through thefluid delivery line 40 and/or through the fluid inlet below thepermeable disk 28.

The electrolyte disposed in the partial enclosure 34 may include anycommercially available electrolytes for electroplating depositiontechniques, electroless deposition techniques and ECMPP techniques. Forexample, the electrolyte may include any sulfuric acid basedelectrolytes, such as copper sulfate, for depositing conductivematerials, or phosphoric acid based electrolytes, such as potassiumphosphate K₃PO₄, that may be used for copper dissolution. Thecomposition of the bath may vary based upon the material used in themanufacturing of the substrate features and the material to be depositedby the electrochemical deposition process.

Polishing of the substrate surface at step 710 can lead to the formationof topographical defects, such as recesses, in the substrate surface. Apatching material, generally a second conductive material, is depositedon the conductive material initially deposited on the substrate,referred to herein as the first conductive material. The secondconductive material is generally deposited on the first conductivematerial of the substrate in the electrochemical deposition system atstep 730. Materials that are barrier materials to the first conductivematerial or passivate, e.g., prevent further chemical activity, such asoxidation, with the first conductive material may be used in filling therecesses. For example, materials, such as platinum, cobalt and tin,which are barrier materials to copper and passivate copper, e.g.,prevent copper oxidation, are preferably used in filling recesses formedin copper features.

Examples of suitable second conductive materials include noble metalions, semi-noble metal ions, Group IVA metal ions, and combinationsthereof. Examples of noble metals include gold, silver, platinum,palladium, iridium, rhenium, ruthenium, and osmium, of which palladiumor platinum are preferred. Examples of semi-noble metals includemanganese, iron, cobalt, nickel, copper, lead, rhodium, carbon,aluminum, and tungsten, of which cobalt, nickel, or tungsten arepreferred. Examples of Group IV metals include tin, titanium, andgermanium, of which tin is preferred. Additionally, binary alloys, suchas cobalt-tungsten, platinum-tin, palladium-tin, and ternary alloys,such as cobalt tungsten phosphate (CoWP), may also be used as the secondconductive material.

The second conductive material is deposited to a thickness sufficient tofill any recesses formed by dishing. Deposition of excess secondconductive material may be used to ensure fill of recesses and othertopographical defects in the substrate surface. The second conductivematerial may be deposited to a thickness of between about 20 Å and about2000 Å on the substrate surface. Excess second conductive material mayalso be used to ensure planarization during subsequent polishingprocesses, such as the barrier layer removal process, which may polishdifferent materials, such as copper containing materials and tantalumcontaining materials at different rates and potentially result indishing of the substrate surface.

Selective deposition of the second conductive material on the firstconductive material may be achieved by taking advantage of thephenomenon in electrochemical deposition processes that some conductivematerials, such as copper, have a greater degree of conductivity over abarrier layer materials, such as tantalum, and greater deposition ofsecond conductive material will occur on the first conductive materialrather than the barrier layer material. For example, an electrolyte anddeposition process could be provided to have a deposition rate of 1200 Åon a copper-containing material in comparison to an deposition rate of200 Å or less on tantalum, thereby allowing fill of topographicaldefects while minimizing material disposed on the barrier layer.Minimizing of material deposited on the barrier layers reduces materialresidues on the substrate surface that may detrimentally affectsubsequent barrier polishing processes.

One such process is self-aligned barrier passivation, which includesselective deposition of the second conductive material on the firstconductive material with reduced or minimal deposition on exposedportions of the barrier layer, with the second conductive materialfunctioning as a barrier layer for the first conductive material. Selfaligned barrier passivation may deposit the second conductive materialon the first conductive metal by an electroless deposition process or anelectroplating process.

The electroless deposition process involves an autocatalyzed chemicaldeposition process and typically involves exposing a substrate to asolution of the metal to be deposited by immersing the substrate in abath or by spraying the solution over the substrate. The noble metal,semi-noble metal, and the Group IV metals described herein as the secondconductive material may be added to the electroless deposition solutionas an inorganic and/or organic salt. Examples of salts that may be usedinclude chlorides, bromides, fluorides, fluoborates, iodides, nitrates,and sulfates. Metal chloride salts, such as palladium chloride (PdCl₂),chloroplatinic acid (H₂PtCl₆), and stannous chloride (SnCl₂), have beenobserved as effective in depositing platinum, tin, and platinum-tinalloys.

The electroplating process includes the application of a bias betweenthe anode and the cathode disposed in the electroplating solution, orelectrolyte, for deposition of the second conductive material on thefirst conductive material. Electroplating solutions typically includemetal ions of the metal desired to be plated as a metal salt, such as ametal sulfate, a metal chloride, and combinations thereof. Typically,the electroplating solution also comprises acids, salts, otherelectrolytes, and other additives.

The bias may be applied at a voltage of about 15 volts or less to thesubstrate surface. A voltage between about 0.1 volts and about 15 voltsmay be used to dissolve copper from the substrate surface and into theelectrolyte. The voltage applied to the substrate may vary dependingupon the substrate surfaces and features in which copper-containingmaterial is to be removed. The application of the bias may vary duringthe process dependent upon the processing condition and results desired.The invention contemplates the use of known electroplating processes andelectroplating process to be developed for depositing the secondconductive material.

One embodiment of an apparatus capable of depositing a nucleation layerby an electroplating process is an Electra Cu™ ECP platform, availablefrom Applied Materials, Inc. of Santa Clara, Calif., of which oneembodiment is described herein. The electroplating apparatus is morefully described in U.S. patent application Ser. No. 09/289,074, entitled“Electro-Chemical Deposition System” filed Apr. 8, 1999, which isincorporated by reference to the extent not inconsistent with thisinvention.

Alternatively, the invention contemplates the use of other depositionprocesses, such as chemical vapor deposition, physical vapor deposition,ionized metal plasma physical vapor deposition among others tonon-selectively deposit material on the substrate surface betweenpolishing steps to minimize or reduce dishing and recess formation inthe substrate surface. An example of a chamber capable of chemical vapordeposition of a nucleation layer is a CVD TxZ™ chamber, available fromApplied Materials, Inc. of Santa Clara, Calif.). An example of a chambercapable of physical vapor deposition is an IMP PVD (ionized metal plasmaphysical vapor deposition) process in an IMP Vectra chamber. The chamberis available from Applied Materials, Inc. of Santa Clara, Calif.Generally, IMP PVD involves ionizing a significant fraction of materialsputtered from a metal target to deposit a layer of the sputteredmaterial on a substrate. Powered supplied to a coil in the chambersupports the ionization of the sputtered material. The ionizationenables the sputtered material to be attracted in a substantiallyperpendicular direction to a biased substrate surface and to deposit alayer of material with good step coverage over high aspect ratiofeatures.

The substrate is then stored in a substrate carrier assembly 138 priorto positioning the substrate in a second polishing station 106 at step740. The substrate is then polished at a polishing station until thesecond conductive material and barrier layer material is removed to atop surface of the dielectric layer or some other intermediate level ofthe dielectric layer at Step 750. The deposited second conductivematerial and barrier layer material may be removed by an abrasivecontaining polishing composition or an abrasive-free polishingcomposition on a conventional or abrasive sheet polishing pad.

This process may be performed by a polishing process which includes oneor more processing steps as necessary to remove the second conductivematerial and the barrier layer to the dielectric layer to form a planarsurface. For example, in a process with copper containing material usedas the second conducting material, and which may be disposed on aportion of the barrier layer in residual amounts, the polishing processmay include a first step of removing the copper containing material anda portion of the barrier layer, followed by a second step to remove thebarrier layer with minimal removal of any conductive material within asubstrate feature.

Suitable polishing compositions and methods for removing coppercontaining materials and barrier layer materials in polishing to thedielectric layer include abrasive-containing polishing compositions andabrasive-free polishing compositions, for example, EPC-5220, EPC-4220,EPC-4200, and SemiSperse 12, commercially available from Cabot Corp. ofAurora, Ill., CUS1201A, CUS1201B, available from Rodel Inc., of Newark,Del., HS-T605 and HS-T505, available from Hitachi Chemical Corp. ofJapan, Cu-10K2, Cu-6.5K, and SEMICOSIL K1020, available from PlanarSolutions of Adrian, Mich., Eterpol EPL 2352, EPL 1453, EPL 2315, andEPL 2313, available from Eternal Chemical Company Ltd. Of Taiwan, andKlebosol 1498-50 and Klebesol 1501-50 available from Clariant Corp. ofCharlotte, N.C.

Suitable polishing compositions and methods for removing coppercontaining materials and barrier layer materials in polishing to thedielectric layer in two step barrier layer polishing processes are morefully described in co-pending U.S. patent application Ser. No.09/698,864 filed on Oct. 27, 2000, and incorporated herein by referenceto the extent not inconsistent with the invention.

Alternatively, depositing the second conductive material and polishingthe second conductive material and the barrier layer material may beperformed concurrently. For example, in the apparatus shown in FIG. 4,an electroless solution may be introduced into partial enclosure 434 viaa fluid delivery line 440 having an outlet 442 positioned above thepermeable disk 428. The permeable disk is a polishing pad. The secondconductive material is deposited on the first conductive material fromthe electroless solution while a polishing pressure is applied betweenthe substrate surface and the polishing pad to remove materialtherefrom. The partial enclosure may also include an anode fordeposition of material on the substrate by the application of a bias tothe substrate while performing a polishing process with the polishingpad. An example of a combination of electrochemical deposition andpolishing process is disclosed in co-pending U.S. patent applicationSer. No. 09/698,864 filed on Oct. 27, 2000, and incorporated herein byreference to the extent not inconsistent with the invention.

The substrate may then be further processed on the same or additionalplaten polishing station, such as by a buffing process, to minimizesurface defects and scratches that may have formed in the substratesurface. Buffing involves polishing the substrate on a platen with a lowapplication of force between the substrate surface and the polishing padand generally using a polishing composition with a low material removalrate compared to conventional polishing processes. An example of asuitable buffing process and composition is disclosed in co-pending U.S.patent application Ser. No. 09/569,968, filed on May 11, 2000, andincorporated herein by reference to the extent not inconsistent with theinvention.

Optionally, a cleaning solution may be applied to the polishing padduring or subsequent each of the polishing process to remove particulatematter and spent reagents from the polishing process as well as helpminimize metal residue deposition on the polishing pads and defectsformed on a substrate surface during polishing or substrate handling.Such processes can minimize undesired oxidation or other defects incopper features formed on a substrate surface.

FIGS. 8A-8D are series of schematic cross-sectional views of a substrateillustrating sequential process steps of one embodiment of the processdescribe herein.

Referring to FIG. 8A, the substrate includes a dielectric layer 810,such as a silicon oxide or a carbon-doped silicon oxide, formed on asubstrate 800. A plurality of openings 840 patterned and etched into thedielectric 810. The openings 840 were formed in the dielectric layer 810by conventional photolithographic and etching techniques. A barrierlayer 820 of a conductive material, such as Ta or TaN for a coppermetallization, is disposed conformally in openings 840 and on the uppersurface of the dielectric layer 810. A copper layer 830 is disposed onthe barrier layer at a thickness (D) between about 8,000 Å and about18,000 Å.

Referring to FIG. 8B, the copper layer 830 is removed using a CMP copperpolishing process with an abrasive free CMP composition. The CMPcomposition removes the copper layer 830 to the tantalum containingbarrier layer 820. Removing the copper material by a CMP compositionhaving a selectivity of about 1:0 between copper and tantalum containingallows for effective removal of the copper layer 830 to the tantalumcontaining layer 820, minimizes dishing of the copper layer 830, andminimizes formation of a non-planar surface. Recesses 850 may form hasformed in the copper layer 830 in the feature 840 by overpolishing ofthe copper layer 830.

Referring to FIG. 8C, a copper material is deposited by an electrolessprocess to overfill copper 860 in the feature 840 with a coppermaterial. Copper material 870 may also have been deposited on thetantalum barrier layer 820 during the electroless deposition process.

Referring to FIG. 8D, the overfill of copper 860 and the barrier layer820 is then polished to the dielectric layer using a second compositionto form a planarized surface 880. Additionally, the dielectric layer 810may be subsequently buffed or polished during the second polishingprocess to remove or reduce scratching or defects formed on thesubstrate surface.

EXAMPLE

An example of an electrochemical deposition process and polishingprocesses according to aspects of the invention described herein is asfollows. A substrate including a low k dielectric layer with featuredefinitions formed therein, a tantalum containing barrier layerconformally deposited on the low k dielectric layer and in the featuredefinitions formed therein, and a copper layer deposited on the barrierlayer and filling the feature definitions formed therein is provided tothe CMP apparatus disclosed above.

The substrate is positioned over first station, and a first polishingcomposition, for example, a polishing composition having a selectivityof about 1:0 between the copper and the tantalum containing layer, isdelivered to the polishing pad. An example of the CMP compositionincludes the EPC-5003 polishing composition commercially available fromCabot Corp. of Aurora, Ill. The substrate is then polished for arequisite amount of time at a rate between about 4000 Å/minute and about10000 Å/minute to sufficiently remove completely or substantiallycomplete removal of the copper layer above the barrier layer. A pressurebetween about 0.5 psi and about 6.0 psi between the substrate and thefirst polishing pad is used to provide mechanical activity to thepolishing process. The substrate is then polished for a requisite amountof time sufficient for complete or substantially complete removal of thecopper layer above the barrier layer.

The substrate is then transferred to an electroless deposition processstation and between about 20 Å and about 2000 Å of copper material isselectively deposited on the copper layer.

The substrate is then transferred to a second polishing station and asecond polishing composition is provided thereto to remove the copperlayer and the tantalum containing barrier layer to the dielectric layer.An example of the second polishing composition is CUS1201A or CUS1201Bcommercially available from Rodel Inc., of Newark, Del. The substrate isthen polished at a rate up to about 1200 Å/minute to remove the barrierlayer materials. A pressure between about 0.5 psi and about 6.0 psibetween the substrate and the polishing pad is used to providemechanical activity to the polishing process. The substrate is thenpolished for a requisite amount of time sufficient for complete orsubstantially complete removal of the copper containing material and theunderlying barrier layer to the top surface of the dielectric layer. Thesubstrate may then be buffed on the third hard pad and then cleanedusing a suitable cleaning solution.

While the foregoing is directed to the one or more embodiments of theinvention, other and further embodiments of the invention may be devisedwithout departing from the basic scope thereof, and the scope thereof isdetermined by the claims that follow including their equivalents.

1. A processing system for forming a planarized layer on a substrate, comprising: a processing platform having two or more processing stations, a loading station, and a substrate transfer device disposed above the processing stations and the loading station; wherein at least one of the processing stations is adapted to polish a substrate surface; wherein at least one of the processing stations is adapted to deposit a material by an electrochemical process; and a computer based controller configured to cause the system to polish a first conductive material from the substrate surface to a barrier layer material, deposit a second conductive material on the first conductive material by an electrochemical deposition technique, and polish the second conductive material and the barrier layer material to at least the top surface of a dielectric layer.
 2. The processing system of claim 1, wherein the computer based controller is further configured to cause the system to perform an electroplating deposition technique, an electroless deposition technique, or an electrochemical mechanical plating process technique at the two or more processing stations adapted to deposit a material by an electrochemical process.
 3. The processing system of claim 1, wherein the computer based controller is further configured to cause the system to deposit the patching material to a thickness between about 25 Å and about 2000 Å.
 4. The processing system of claim 1, wherein the computer based controller is configured to cause the system to deposit a second conductive material on the first conductive material by an electrochemical deposition technique and polish the second conductive material and the barrier layer material to a top surface of the dielectric layer concurrently at the same processing station.
 5. A substrate processing chamber adapted for processing a substrate comprising: a substrate support, comprising: a substrate receiving surface; a vacuum port; vacuum grooves in communication with the vacuum port; and a fluid source; a fluid input coupled to the fluid source and adapted to deliver a processing fluid to a substrate disposed on the substrate receiving surface; and a fluid output adapted to drain the processing fluid from the processing chamber.
 6. The substrate processing chamber of claim 5, wherein the substrate support is adapted for face-up processing.
 7. The substrate processing chamber of claim 5, wherein the substrate support is adapted to rotate.
 8. The substrate processing chamber of claim 5, further comprising a polishing head assembly comprising: polishing media; and a polishing media support.
 9. The substrate processing chamber of claim 8, further comprising an electrode contacting the polishing media or the polishing media support.
 10. The substrate processing chamber of claim 9, further comprising a spacer disposed between the electrode and the polishing media.
 11. The substrate processing chamber of claim 8, wherein the polishing media comprises a conductive polishing media.
 12. The substrate processing chamber of claim 8, wherein the polishing head assembly is adapted to rotate.
 13. The substrate processing chamber of claim 8, wherein the polishing head assembly has a smaller diameter than the substrate diameter.
 14. An electrochemical deposition system, comprising: a mainframe having a mainframe wafer transfer robot; a loading station disposed in connection with the mainframe; one or more electrochemical processing cells disposed in connection with the mainframe, the one or more electrochemical processing cells comprising: a substrate support, comprising: a substrate receiving surface; a vacuum port; vacuum grooves in communication with the vacuum port; and a fluid input coupled to an electrolyte supply and adapted to deliver an electrolyte to a substrate disposed on the substrate receiving surface; and a fluid output adapted to drain the processing fluid from the processing chamber; one or more polishing platens disposed in connection with the mainframe; an electrolyte supply fluidly connected to the one or more electrochemical processing cells; and one or more polishing fluid supplies connected to the one or more polishing platens.
 15. The system of claim 14, further comprising a polishing head assembly disposed adjacent the one or more electrochemical processing cell and comprising: polishing media; and a polishing media support
 16. The system of claim 15, further comprising an electrode contacting the polishing media or the polishing media support.
 17. The system of claim 15, further comprising a spacer disposed between the electrode and the polishing media.
 18. The system of claim 14, further comprising a system controller for controlling an electrochemical deposition process, an electrochemical removal process, a polishing process, or combinations thereof.
 19. The system of claim 14, further comprising a spin-rinse-dry (SRD) station disposed between the loading station and the mainframe.
 20. The system of claim 14, further comprising a thermal anneal chamber disposed in connection with the loading station. 